The present invention generally relates to endovascular grafts and, more particularly, to a graft and process for bridging an abdominal aortic aneurysm disposed in the aorta near the renal arteries in which the graft is expanded against a portion of the aortic wall above one or both renal arteries.
Abdominal aortic aneurysms are potentially life threatening defects which generally lie in a section of the aorta between the renal arteries and the iliac arteries. In some cases, an abdominal aortic aneurysm may extend into either or both of the iliac arteries.
Abdominal aortic aneurysms are commonly treated using surgical techniques. Surgical treatment of abdominal aortic aneurysms is however a complicated procedure associated with high risk. As an alternative to surgery, a wide variety of grafts including, for example, stented grafts or stent-grafts, have been proposed for bridging and excluding abdominal aortic aneurysms. The use of these grafts is however limited. In most cases, an abdominal aortic aneurysm is either left untreated or is treated surgically. Even in cases using a graft, the procedure is sometimes terminated in favor of surgical treatment.
The present invention generally provides grafts for bridging a main vessel having a defect disposed near one or more branch vessels extending from the main vessel. Embodiments of the invention are particularly suited for bridging abdominal aortic aneurysms having minimal or no proximal necks, a significant factor limiting the use of conventional grafts for bridging abdominal aortic aneurysms.
One particular embodiment of the invention provides a stent-graft for bridging an aneurysm in an aorta disposed below two renal arteries. The stent-graft includes a graft material defining two renal apertures each oriented to align with one of the two renal arteries when the stent-graft is in an expanded state. The stent-graft further includes a stent system for supporting the graft material in a contracted state wherein the renal apertures are contracted and the expanded state wherein the renal apertures are expanded. The stent system when in the expanded state, is adapted to press against a portion of the aortic wall above the first renal artery and against a portion of the aortic wall above the second renal artery. Each renal aperture may, for example, have an area as large as or larger than the opening of the respective renal artery.
In accordance with another embodiment of the invention, the graft material defines a mesenteric aperture oriented to align with a superior mesenteric artery when the stent-graft is in an expanded state. In accordance with yet another embodiment of the invention, the stent-graft material further defines a celiac aperture oriented to align with a celiac axis artery when the stent-graft is in the expanded state.
A graft, consistent with another embodiment of the invention, includes a tubular member which defines one or more apertures and is adapted for positioning against a wall of a main vessel above one or more branch vessels. Each aperture defined by the tubular member is alignable with at least one of the one or more branch vessels and has an area which is greater than the opening of the respective branch vessel(s) when the graft is positioned against the wall of the main vessel.
In accordance with another aspect of the invention, a process of bridging a defect disposed in a main vessel near one or more branch vessels is provided. Consistent with the process, a graft which defines one or more apertures is inserted in a contracted state within the main vessel. The graft is aligned within the main vessel such that each aperture aligns with at least a respective one of the branch vessels and expanded into a expanded state wherein the one or more apertures align with the one or more branch vessel and the graft presses against the main vessel wall. The process can, for example, be used to bridge an abdominal aortic aneurysm disposed in an aorta near the renal arteries.
In accordance with another aspect of the invention, a process for manufacturing a customized graft for bridging a defect disposed in a main vessel near one or more branch vessels is provided. The process includes developing a three dimensional image of an interior of the main vessel including the one or more branch vessels. Using the three dimensional image, a customized graft is formed having one or more apertures configured to align with the one or more branch vessels when the graft is positioned against the wall of the main vessel.
The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description which follow more particularly exemplify these embodiments.